MW, Swallowing the Earth by Osamu Tezuka. lol, there is certainly no moe or giant robots here. He is clearly affected by the writers and events of his generation.
Roshomon & related short stories by Akutagawa. I don't think I even need to explain who or what this is. I am reading it in Chinese though, since my Japanese reading comprehension has completely gone to like 6th grade or something.
SuperFreakonmics by Steven D. Levitt. An updated book full of interesting new data and new issues that seem unrelated to each other but somehow a direction causation can be observed through careful examination of the said data.
I am also looking at the possibility of a few books that sounds interesting but I don't have the time for - 2666, 120 days, The Tales of Genji, Wind up Bird's chronicle, Thousand Cranes, One over the cuckoo's nest, etc.